Just to throw my 2c in, there's unquestionably a learning curve, too. "Driver break-in"? Hehe.

But my first full year driving my 07 TCH I never got a single tank measured above the 40 mpg mark (though the MFD gave me credit for 2 in August 06). And during the first winter I went as low as one tank at <29 mpg. But sometime that spring, I suddenly figured out something that may or may not be accurately reflected in the FAQ (I know I tried to help get it explained properly but haven't looked in quite a while), which other people had mentioned.

Basically when you start the car cold (wasn't already running and warm shortly before), there are several stages. First is the initial warm-up, where the car won't shut down the ICE until it gets to a satisfactory temp. Next is what I'll call (at least if you're careful) a secondary warm-up stage. If you don't make sure to get your car to the third stage, this second stage is really how you operate for the entire trip, btw. If the conditions never come up to go to the third stage it won't happen.

But the second stage is when it's generally warmed up, and if you come to a complete stop with the ICE running, the car will shut it down right away. And if you come down from >40 mph in this stage, you'll also get into EV mode. And you can drive in full EV mode as long as you don't exceed ~40 mph, and you never kick in the ICE again (either by accelerating, or low battery). But if you're moving under 40 mph and your ICE is burning gas, there's no way for it to ever go back to EV mode without coming to a complete stop, or getting your speed up over 40 mph.

For that you need to be in the third stage. That's where your car is fully warmed up, generally takes maybe a mile or so after it's generally warm (for me, it's often after about a mile in warmer weather, or 2 or more in colder weather), and you come to a complete stop and your car _doesn't_ shut down the ICE immediately. What happens instead is that it runs for about 7-8 seconds, then shuts off. At this point you're in what others have called "full hybrid mode", when the car will freely flip between gas-burner and EV. In this stage you can be driving 30 mph, hit the gas to go up a small hill, then take your foot off the accelerator and the ICE will just shut off again (battery, etc permitting). In stage 2, in the same circumstances, you'd hit the gas, and you'd be stuck burning gas until you stopped. I can't say how much fuel that is, but it's not zero.

My second big revelation was when I found that a suburban route for my commute through several towns, mostly just doing 30-40 mph, even with a couple notable hills, gave me a major boost to my FE. Went from doing a 20 mile commute on the interstates (taking 30-45 minutes per day depending on traffic) to a ~16 mile commute through towns, for consistently ~45 minutes, and much better mileage.

And of course the usual tips like park where you can just drive out when possible (I always back into parking spots because I can do that on battery, while backing out would burn gas), I even turn it off when it's cold and I'm forced to stop while it's still in my "stage 1" where it won't turn off until it warms up.

Otherwise, keep your eye on the battery gauge, and make sure your use of EV mode never lets it get so low the ICE turns on just to charge the battery. That leads to 0 mpg.

Hope these help, including your question about when the ICE shuts off.

BTW random note, I've had times when, never getting into my "stage 3", I end up on the highway, and when I finally get somewhere I can do a full stop, the ICE doesn't seem to want to shut off at all no matter how warm it should be. Not sure what's going on there, but I think I determined if I could turn the car off and start it up again it'd be all warmed up for a quick progression to stage 3.

 

I can add something that I learned from Tom in Denver. Press the ECO button once you start the engine. It's the button next to the fuel-door button. With the heater on maybe low fan, the ECO will stay engage as long as you don't go higher than 85 degrees. Look for the ECO indicator in the center of the heater readout.

It sure helps to stop the engine when stopped at a red light. It seem to help me get into the EV mode easier even when the temp is in the mid to high 30's.

 

chestr wrote: "there's unquestionably a learning curve, too. "Driver break-in"?"

We should consider requiring all new vehicles to have a Miles-per-Gallon meter, large enough to be read easily while driving, next to the speedometer. I think it would help most drivers to be aware of how their driving behavior affects their fuel cost.

What do you think would happen to our national average miles-per-gallon? I think it would increase dramatically. And, I think it would cost a lot less than most alternatives.

Most people do change their behavior when they know that doing so will benefit them financially. However, many people actually do not know that driving behavior affects fuel mileage, and most do not know how specific driving behaviors affect their mileage, or how to drive to obtain better mileage. When you only see the cost when you fill the fuel tank, there is not enough "feedback" to learn specific driving behaviors. One feedback stimulus per week is not enough to learn behaviors that require decisions every few seconds.

An MPG meter provides immediate "feedback", which helps us to learn how our driving behaviors affect fuel mileage. And, the driver gets a feedback stimulus every time he/she glances at it.

 

Much like the speedometer?

A FE gauge will provide feedback only to those that seek it - witness folks doing 80+ on the roads with a 65 MPH speed limits. Much like ignoring the excess speed, there will be a percentage (maybe majority) of drivers that ignore that feedback.